The overall objective of the proposed research is to create a eukaryotic mutagen monitoring system, a series of waxy pollen mutants of known mutation origin in barley, that can 1) Be used in and around sources of air pollution (factories, laboratories, and reactors), chemical waste dumps, where chemicals are applied in farming practices, and in mobile air pollution testing laboratories, 2) Reveal very low levels of genetic damage, and 3) Record the nature of mutations induced at the DNA level (base substitution, frameshift, deletions). Detailed analysis of spontaneous reversion rates and mutagen sensitivity of selected waxy mutant lines will be continued--the latter will be achieved by spray experiments with appropriate mutagens. The computer program for the statistical analysis of pollen mutant frequencies will be completed and applied to data. Allelic testing, intragenic mapping, and chromosome analysis of the mutant lines will be continued. New mutants induced by appropriate mutagens will be selected and analyzed for stable spontaneous reversion frequencies and mutagen sensitivity. The genetics and breeding research will continue to establish flanking markers for the waxy locus and to develop dwarf, early maturing, highly adapted waxy mutant lines suitable for application in mutagen monitoring and screening.